Dynamics of trace bioelements and their effects on the ecosystem in the marine environment

海洋环境中微量生物元素动态及其对生态系统的影响

基本信息

批准号：
13440166
负责人：
SOHRIN Yoshiki
金额：
$ 9.66万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13440166/
关键词：
oceanography analytical chemistry trace metals bioelements phytoplankton chelating ligands carbon dioxide global warming 分析学

项目摘要

1. An analytical method for the determination of trace metals in seawater has been developed on the basis of chelating adsorbent column extraction-ICP mass spectrometry. The distributions of Fe, Co, Ni, Cu, Zn, Cd, and Pb in the North Pacific have been observed. The concentration of acid-dissolvable Fe is higher than that of dissolved Fe, showing the dominance, of labile particulate Fe in seawater. Although dissolved Fe and Zn in summer surface water are depleted in the subarctic North Pacific, they are abundant in the subtropical North Pacific.2. We have found that there was an east-west gradient in the photosynthetic, competence of phytoplankton in the subarctic North Pacific in the summer of 1999 and that the difference was probably caused by Fe levels in seawater. A dramatic floristic shift was found by pigment signatures.3. We have participated a mesoscale Fe enrichment in the western subarctic North Pacific (SEEDS2001). The photochemical quantum efficiency of algal photosystem suggested that the phytoplankton community was suffered from Fe stress and the Fe enrichment improved the physiological condition. There was some 5 nM of labile particulate Fe in the field. It had been supplied by aeolian dust, but it was not readily available for phytoplankton. The decrease in dissolved Co, Ni, Cu, Zn, and Cd occurred during the phytoplankton bloom.4. A sensitive analytical method has been developed using chelating ligand exchange-adsorptive cathodic stripping voltammetry, and Fe ligands derived from eukaryotic phytoplankton have been detected.5. We have developed a technique to separate and purify RNA from phytoplankton under Fe stress. The composition change in membrane proteins of Fe-stressed phytoplankton has been observed.6. Incubation experiments of phytoplankton have shown that the growth of phytoplankton is controlled by the species and concentrations of co-existing organic ligands.

1. 建立了基于螯合吸附柱萃取-ICP质谱法测定海水中痕量金属的分析方法。已观测到北太平洋铁、钴、镍、铜、锌、镉和铅的分布。酸溶性铁的浓度高于溶解性铁的浓度，表明海水中不稳定颗粒铁占主导地位。尽管夏季地表水中溶解的Fe和Zn在北太平洋亚寒带地区逐渐减少，但在北太平洋副热带地区却十分丰富。2．我们发现1999年夏季北太平洋亚北极浮游植物的光合能力和活性存在东西向梯度，这种差异可能是由海水中铁含量引起的。通过色素特征发现了显着的植物区系转变。3．我们参与了北太平洋亚北极西部地区的中尺度铁富集活动（SEEDS2001）。藻类光系统的光化学量子效率表明浮游植物群落遭受了Fe胁迫，Fe的富集改善了其生理状况。现场存在约 5 nM 的不稳定颗粒铁。它是由风尘提供的，但浮游植物却不容易获得。浮游植物水华期间溶解的Co、Ni、Cu、Zn、Cd含量减少。 4．采用螯合配体交换吸附阴极溶出伏安法建立了灵敏的分析方法，并检测到了真核浮游植物中的Fe配体。 5．我们开发了一种在铁胁迫下从浮游植物中分离和纯化 RNA 的技术。观察了铁胁迫下浮游植物膜蛋白组成的变化。 6．浮游植物的孵化实验表明，浮游植物的生长受共存有机配体的种类和浓度控制。